<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<!--view层 模板-->
<div id="app">
    下拉框：
    <select v-model="selected">
        <option value="" disabled>-请选择-</option>
        <option>A</option>
        <option>B</option>
        <option>C</option>
    </select>
    <p>value:{{selected}}</p>
</div>
</body>

<!--导入js-->
<script src="https://cdn.jsdelivr.net/npm/vue@2.5.21/dist/vue.min.js"></script>
<script>
    var vm = new Vue({
        el: "#app",
        data: {
            selected: ""
        }
    })
</script>
</html>
